 (defonce ^{:doc "Controllers which are currently bound to shows,
   indexed by the controller binding ID."}
   active-bindings (atom {}))
-
-(defn sign-velocity
-  "Convert a midi velocity to its signed equivalent, to translate
-  encoder rotations, which are twos-complement seven bit numbers."
-  [val]
-   (if (>= val 64)
-     (- val 128)
-     val))
 
 (defn- overlay-handled?
   "See if there is an interface overlay active which wants to consume

  ;; TODO: Do other things when synced.
  ((:tap-tempo-handler controller)))

(defn- enter-metronome-showing
  "Activate the persistent metronome display, with sync and reset pads
  illuminated."

  (add-overlay controller
               (reify IOverlay
                 (captured-controls [this] #{3 9 20 21})
                 (captured-notes [this] #{0 1})
                 (adjust-interface [this controller]
                   ;; Make the metronome button bright, since its information is active
                   (swap! (:next-text-buttons controller)
